Nanofabrication and its Evolution
Intro In this section we explore the prospects of nanotechnology, it’s likely evolution, and the products and techniques that may be of most importance to TMP. Nanotechnology is a common topic in popular culture today even if the general public has only a dim comprehension of what it’s all about, the common portrayals of it in the media generally rather poor. Most people are aware that it concerns the manipulation of matter on a molecular scale, presumably with some form of microscopic machines or robots. They may also know that a myriad of seemingly magical capabilities are attributed to this technology and the material it may produce and that Singularity futurists promise all kinds of miraculous breakthroughs in science and medicine resulting from it—including even a ‘cure for death’. Some may also be aware of supposed doomsday threats from the technology if it is allows to ‘run away’ uncontrollably. Nanotechnology terms have also been adopted by marketing people as new multipurpose labels to tag onto products to characterize them as novel and futuristic—whether or not they actually have anything to do with this technology. As so often happens, new technologies inspire much hype and wild speculation leading to the usual overestimation of the near-term and underestimation of the long-term. Let’s try to get to the bottom of this and look at what and where this technology actually is, where it’s likely to go, and how it may, realistically, impact our future civilization. Materials and Magic What are the likely, realistic, benefits of nanotechnology? Current hype about the technology makes promises so grand it’s hard to take seriously. Singularity futurists will casually talk of an age of Post Scarcity and even immortality. But no one technology alone is going to make such things happen, though nanotechnology may prove to be a key factor. But what can we more plausibly expect, particularly in the near-term? The chief near-term impacts of nanotechnology are likely to be in terms of the way we make things and what me make them from, with the most immediate impacts relating to microelectronics whose production processes already strongly relate to doing things at the nanometer scale. In each historic age of civilization predominate industries have been reflected in predominate materials in common use. Prior to the Industrial Age, stone, wood, natural textiles, ceramics, lower-energy metals like iron, pewter, bronze, brass, and copper, animal by-products comprised the mix of materials commonly used. With the Industrial Age came increasing use of iron, steel, aluminum, and—more significantly on the domestic level—plastics. Across the 20th century plastic became the defining material of the age. It is everywhere, in most household products, the packaging for just about everything sold, the clothes we wear, the houses we live in. In our early Post-Industrial era we see the rise of composites, particularly carbon fiber composites, and new advanced ceramics taking the place of high performance metals like steel. We are building cars, planes, engines and the like out of these new non-metallic materials. The era of nanotechnology is sometimes referred to as the Diamond Age in reference to the likely predominance of ‘diamondoid’ materials made through nanofabrication from abundant (to the point of pollution) carbon in our environment. (hence the name of the well known Neil Stephenson science fiction novel) Diamondoids promise us a broad spectrum of materials radically stronger and lighter than the highest quality steel and as cheap and ubiquitous as plastics are today. Initial forms are currently very simple ‘nanofibers’ or ‘nanotubes’—often called ‘buckytubes’ because they derive from the geodesic-structured carbon molecule named for Buckminster Fuller called buckyballs—and ‘nanotapes’ made of such fibers using our very nascent forms of nanofabrication deriving from organic chemistry. These materials are becoming the basis of advanced composites which may supplant carbon composites in high-performance applications, though at present they remain far too expensive for mundane uses and will most likely be limited to military aircraft and spacecraft uses for a while. It is also finding uses in active systems, being combined with other materials to make various sensors, filters, hydrogen storage mediums, and even synthetic muscles that may soon give robots a new level of naturalistic kinematics. Perhaps the most dramatic potential application of these early diamondoid materials is the long speculated Space Elevator, which is discussed in TMP2 as a later development of the Bifrost launch system program. The possibility of deploying a tether structure between the Earth’s surface and GEO orbit hinges on the anticipated super-strength of these nanofiber materials. Nanofiber, at present limited to short lengths, is also soon likely to find itself an addition to a variety of other materials such as concretes, ceramics, and plastics in the form of a homogenous or aligned admixture intended to radically increase strength—much as steel, aluminum, and glass fiber are already combined with these same materials. These types of composites will eventually see more everyday uses, particularly in buildings, automobiles, and various kinds of engines and motors. As bulk diamondoid materials are realized—materials that are diamond composition all the way through—they will begin to supplant high performance composites, metals, and ceramics and, as they become cheaper, eventually glass and plastics allowing them to penetrate into common domestic uses. We are likely to first see these in ‘extruded’ forms of panels, beams, structural tubes, and other shapes similar to the uses of aluminum today because their early forms of fabrication may rely on production processes in some ways mechanically similar to 3D printing or stereo-lithography. They will probably not lend themselves to process akin to casting or injection-molding and milling them may be more complex than working metals. This will afford very diverse topologies at small scales, but at large mass-production scales favor simple multi-purpose shapes that can be produced continuously as commodity products, like extruded aluminum profiles. An effective technique of ‘welding’ or ‘bonding’ diamondoids in field conditions may prove difficult for some time and so it’s likely that, much as with aluminum profiles, large structures will be made with mechanical connections and systems like modular space frames and post & beam systems. Perhaps one of the most visibly common applications of these by this time may be remarkably thin and strong diamond glass windows as a general replacement of conventional glass and plastic for optical uses, architectural uses, solar panels, and digital displays. But there may also develop something of a craze for 3D printed ‘diamond glassware’. Diamond optical fibers are another powerful possibility that may see some breakthroughs in ground telecommunications. Another remarkable class of diamondoid materials that may be developed is metamaterials, already being explored today. Metameterials are materials which exhibit the physical and chemical characteristics of other kinds of materials as a consequence of unique nano-scale structural configurations. One of the key applications of this has been in the development of alternative catalytic materials that may be cheaper than conventional kinds or exhibit benefits of longer life or more reactive efficiency. This has been especially important to battery and fuel cell development. But we are also seeing such materials expand into many other physical characteristics such as optical, thermal, and electrical properties. With expanding means of tailoring the physical structure of materials with complex and highly precise topologies, a whole new spectrum of metamaterials become possible and the engineering applications of diamondoids in particular may greatly expand. But perhaps the most remarkable of anticipated future materials emerging from nanotechnology may be ‘smart’ materials and polymorphic composites. Smart materials would be materials that integrate electronics, photonics, and other types of machines redundantly into their physical structure, affording sensing capabilities, active thermal properties, and many other potential capabilities. Today smart materials research largely concerns the ability of sensing and feedback—materials that can sense and automatically/passively respond to light, heat, or physical contact by changing their properties in some way. With the ability to integrate all sorts of nano-scale mechanisms into the matrix of materials many other capabilities become possible, resulting in structural elements with remarkable hybrid functions. Structural materials that can emit light, monolithic materials that can be variably translucent or transparent, solar-energy collection built-into just about anything. Most remarkable of all may be the Polymorphic Composites; materials that physically change their shape in controlled ways in response to the environment or control signals. Imagine a house whose walls respond to temperature, solar gain, or season by changing their insulation and thermal mass properties. Imagine a car with shape memory so if it is bent or dented in a collision, morphs itself back into working shape. Imagine aircraft that can transition from sub-sonic to super-sonic modes of flight by transforming their wing shapes in flight. Imagine rockets that can radically change their shape from launch, to orbit, to re-entry. NASA has already begun speculating on the aerospace applications of such amazing materials. As nanofabrication techniques expand in flexibility there may be a general impetus to seek continually expanding uses of diamondoid as a means to combat Global Warming by literally extracting the carbon we have dumped into the atmosphere for centuries and putting it in stable form in our built habitat in as many ways as possible. It is hard for us to visualize the impact of such materials in our contemporary context. If what materials scientists anticipate is correct, we are looking forward to materials who properties of strength, thinness, and lightness are such that it would be like presenting a piece of aircraft grade aluminum, a spool of kevlar, a block of lucite, or a wafer of silicon to a medieval craftsman. They would regard these things as if they came from another world. In the areas of microelectronics, microphotonics/microoptics, and micro-electro-mechanical systems nanotechnology basically offers much of the same sort of improvements these fields demonstrated across the 20th century, but potentially in leaps of orders of magnitude in capability that may re-write the traditional rules of progress like Moore’s Law. But the much anticipated warp-factor of technical advance is the envisioned combination of these new levels of IT performance with emerging artificial intelligence—and not necessarily the kind of AI we have been taught to expect by SciFi media. Non-sentient or ‘passive’ AI is what will have the most impact on science, engineering, and communication, leveraging human potential and automating and accelerating the more time-consuming aspects of research, development, and systems programming. This is the foundation of the idea of a technological ‘singularity’ so long anticipated by futurists. The possibility of computers that learn and self-program to solve problems presented/represented in high-level forms. There is also a much-anticipated cross-over of nanotechnology into medicine, offering new possibilities for manipulating biochemistry at a cellular and sub-cellular level. The same technology that will allow us to build machines on the scale and complexity level of cells may afford us radical new abilities to work with life on that same level, intervening in biological processes as never before and with increasing degrees of dynamic, intelligent, automation. It is in this we find the root of the idea of nanotechnology as a key to the possibility of human immortality, providing means of intervening directly and comprehensively in the processes of aging and also a means to getting closer to a general characterization of the biophysics of the human consciousness itself and the potential to intervene in, interface with, and reproduce it. It is here we encounter the notion of nanotechnology partnering with artificial intelligence research and leading to the radical prospect of a portability of human consciousness—a virtual immortality. As discussed elsewhere in TMP2, we foresee an emerging cultural perspective on human life and consciousness as something potentially independent of the machinery of biology, and not in some mystical spiritual sense but in the form of transferable information. Let’s now look a little deeper at how nanotechnology is likely to work and evolve and the mechanisms and processes by which it may realize these possible future wonders. Disciplines of Nanotechnology The modern concept of nanotechnology is said to have its origins in a paper by famous physicist Richard Feynman who proposed a multidisciplinary study into the possibility of physically manipulating matter at the ‘nanometer; level to create combinations and structures not normally possible by means of chemical reaction. Dubbed ‘mechanosynthesis’, this concept garnered only modest scientific interest until the fields of microelectronics—based predominately on processes of micro-lithography—emerged, began working increasingly close to nanometer scales, and evolved to be a critical (and profitable) aspect of information and telecommunications technology. Contemporary and popular ideas about nanotechnology originate largely in the work of Dr. Eric Drexler who advocated and cultivated nanotechnology as a formal multidisciplinary science and engineering field and whose lighter books popularized the concept, bringing it to the attention of the mainstream culture and and the imaginations of contemporary futurists and science fiction writers. Unfortunately, he is also the source of doomsday fears about the technology, his early cautions about the controls needed for developing nanomachines and his suggestion of ‘grey goo’—the idea that runaway self-replicating nanomachines might uncontrollably convert the matter around them into a lifeless mass—being exaggerated and exploited by sensationalist journalists and SciFi writers, always eager for another dystopian fantasy to scare people with. Generally dismissed today, these notions persist in the popular culture, conditioned as it is to obsess over imaginary fears and disasters. As a field, nanotechnology has suffered from its hype, creating unrealistic near-term expectations. Working with matter at the nanometer scale is challenging, the physical behavior of things very different from our common everyday experience and only marginally explored even after many decades of science and engineering working at microscopic scales. But things are advancing rapidly and the field may soon begin living up to some of its hype, producing real and unexpected impact even before it has arrived at magical capabilities commonly attributed to it. Drexler’s early work focused largely on nano-mechanisms and fabrication by ‘mechanosynthesis’ but today we consider a broader spectrum of techniques and methodologies as parts of the evolution of this technology, each contributing to a line of development that may culminate in the kind of technology Drexler described but each producing, on their own, whole industries of products and capabilities. Let’s look at these individually; Biosynthesis Life itself produced the original nanomachines, evolving our planet’s biosphere and building our own bodies from the molecular level up through incredibly complex systems of biological mechanosynthesis. Through agriculture, we have been exploiting this particular branch of nanotechnology for millennia, every plant and animal we cultivate a complex nanomachine system converting materials into goods we use. So it is only logical that, in seeking to understand and devise nanosystems of our own, we look to nature and biology as sources of knowledge. This has led to processes of biosynthesis; where living organisms—microorganisms usually—are adapted and harnessed to perform industrial processes. This has already become valuable in the pharmaceuticals industry and has begun moving into such large scale activities as the bulk production of biofuels by algae and the extraction of heavy metals by plants in what is commonly called ‘phytomining’. Such phytomining and biosynthesis has been discussed elsewhere in TMP2 as likely means to In-Situ Resource Utilization on other planets. Toward the end of the 20th century the field of biotechnology caught the popular imagination much as nanotechnology today and many of the same technical breakthroughs were anticipated for it. The field enjoyed a brief boom in investment and research much as the IT industry did, but, a victim of its own hype, it was eventually dragged-down by patent system abuse, lack of research cooperation, public fear, corporate fraud and excess, and other factors. Due to the culture of the pharmaceuticals industry it emerged from, it failed to cultivate the kind of vital industrial ecology that catalyzed the rapid progress in IT and presents a cautionary example to other branches of nanotech development. Nanolithography Nanolithography derives from the microlithography with which much of our contemporary electronics systems are made and is a very active area of nanotechnology today, since it has evolved out of the established electronics industry. Lithography is the general term for processes related to printing and photography, originating in the 16th century art form of print lithography where images are drawn on a stone plate with a wax or grease pencil, the plate then treated with a hydrophilic resist (gum arabic) and loaded with ink which accumulates on drawn areas to be transferred to paper in a mechanical press. This is the root technique underlying most modern printing and photography (originally photo-lithography) techniques. In microlithography such techniques are taken to a microscopic scale to ‘print’ layers of dopants and other materials on a semiconductor substrate like silicon, creating complex electronic circuits of very tiny scale. Nanolithography takes these techniques to the near-molecular scale producing, at present, the tiniest of integrated circuits so far produced. Nanolithography already crosses the boundaries of other nanotechnology disciplines, employing many of their techniques. Biosynthesis techniques have been proposed for nanolithography and the use of Scanning Tunneling Microscopes (STMs) and Atomic Force Microscopes (AFMs) have been employed as means of ‘printing’ with discrete atoms. In all cases, the basic idea is to find ways to ‘print’ structures at ever-smaller scales of detail in the hopes of making integrated circuits—as well as some micro-machines—of steadily increasing density. Stochastic Assembly Stochastic Assembly is a family of techniques by which nano-scale structures are produced by largely random interactions, usually in some kind of fluid medium, under some kind of externally controlled conditions of temperature, pressure, specific gravity, light, vibration, and so on. It relates to conventional chemistry, which is essentially about the stochastic chemical reaction of combined materials, but differs critically in that the objective is to produce very specific molecular structures not commonly possible by simple chemistry. Consequently, this is most directly related to organic chemistry, protein chemistry, and biotechnology with much work relating to the pharmaceuticals industry but, more recently, it has found applications in nanolithography and, at microscopic rather than nanoscopic scales, uses in the micro-manufacture of displays, memory devices, and other electronics. Protein synthesis through organic chemistry may be one of our first means to the creation of free-roaming ‘assembler’ nanomachines—most likely simple carriers of molecules that deposit their ‘payload’ when they have stochastically (randomly) contacted a production object’s surface in the right orientation and location. In TMP2 we anticipate the imminent possibility of a kind of nanofabrication system called a Mixer Plant that is derived from today’s automated pipette, gene sequencing, and microfluidic systems which conducts vast numbers of stochastic combination sequences to assemble complex nanomachines in very small volumes of process solution. This may result in some of our first simple forms of nano-assembler robots and the ‘mass production’ of simple molecular components used in other nanofabrication processes. Direct Mechanosynthesis Direct Mechanosynthesis is the use of machines for the directed/controlled physical manipulation of molecules and atoms to create highly precise and complex structures that may not necessarily be possible by conventional chemistry and other means of fabrication. This is the approach most commonly envisioned as nanotechnology—with the machines most commonly imagined being ‘nanobots’; free-roaming nanoscale robots. At present, though, no such nanobots exist and their realization is proving a bit more challenging than once anticipated. A number of other machines dominate today’s early exploration of mechanosynthesis, chief among them the Atomic Force Microscope (AFM) which has in recent years evolved into a kind of crude nanoscale machine tool for moving around discrete atoms and molecules and combining them on flat substrate surfaces into simple structures. AFMs use microscopic probes as both a sensor and tool, these becoming increasingly refined and specialized in design and function. In TMP2 we anticipate the evolution of such machines into an increasingly automated and multi-functional machine called the NanoLathe—though in practice it may be more akin to a nano-scale CNC milling machine and pick-and-place robot. Currently such machines are limited to simple experimental structures but with more complex computer control, multiple special-purpose probes, and automated materials delivery we anticipate these may one day be employed chiefly in the production of Nanochips; fixed position nanomachines akin to today’s MEMS (micro-electro-mechanical systems) that would be the basis of other larger machines. We will discuss these in more detail later. Evolution of a Comprehensive Nanofabrication Given these basic contemporary approaches to nano-scale manipulation, where are we likely to go from here? These disciplines are likely to extensively cross-fertilize over time leading to innovations we cannot hope to predict. But there are a number of technologies that we anticipate as likely eventualities that define a relatively clear path of evolution for nanotechnology, realizing the many capabilities anticipated for it. It’s always risky to predict very specific outcomes. The inventors of the telephone could scarcely imagine today’s smart phones. (how long was the video-phone anticipated and look at how that actually came about…) But we can suggest some seemingly likely possible forms for the sake of illustrating stepping-stones on a likely evolutionary path. Nanocarriers and Nanocollectors The first of these stepping-stones may be Nanocarriers which, to some extent, already exist in organic chemistry. Nanocarriers are engineered molecules—proteins in particular—that would function as carriers of other molecules in a fluid medium which they are intended to release under specific conditions or signals—usually the presence of another signal chemical/molecule, a certain type of light, a certain temperature, etc. Nanocollectors are related structures that are designed to latch-onto very specific molecules so they can be separated from a solution. As we noted, these already exist. The key innovations anticipated here is the ability to tailor and mass produce these on demand and to make forms that have multiple programmable modes of function, making them precursors of nanobots. They would also be precursors of the molecular packaging methods employed in later NanoSoup molecular distribution systems. Nanochips The next-most imminent of these is a technology called the Nanochip. A Nanochip is a fixed-purpose nano-scale machine system built on a fixed substrate material like the silicon substrate of an integrated circuit and is a likely product of the combination of NanoLathes, nanolithography, and some types of stochastic assembly. It seems most likely because it is a logical extension of already existing integrated circuit and micro-electro-mechanical systems and the processes used to make those. Nanochips may do for industrial processes what integrated circuits did for electronics. Formed into fixed-mounted chips or chip-arrays in assemblies similar to fuel cells, they will initially function like tiny factories that either mass-produce certain molecular structures from simpler elements or do the reverse, gathering and dis-assembling one kind of molecule and outputting another. They will at first be limited to functioning with materials in fluid suspension—either as liquids or gasses. These will be used to perform such tasks as precision chemical sensing, synthesizing drugs, chemicals, and complex molecular structures, functioning as pseudo-catalysts, refining chemicals with low-energy, removing contaminants in processing streams, recycling air and water, extracting carbon and other pollutants from air and water. These systems might ultimately offer a powerful solution to Global Warming through the use of atmospheric and oceanic carbon collectors that, using renewable energy and vast Nanochip arrays, simply take carbon out of our ambient environment and convert it into feedstock materials for industrial production of diamondoid materials and products. Combined with microelectronics and microphotonics systems, Nanochips would also serve as the basis of a new class of extremely powerful computing and communications systems. These would combine nanoscale molecular-mechanical data processing systems with more conventional systems to link them to more conventional digital electronics systems, evolving the basis for integral computing for later, more complex, nanomachines. These simpler forms of Nanochips are also likely to become the basis of various miniature or microscopic stationary medical implants that can integrate with the body’s own biochemistry, powering themselves like living cells do and performing various sensing and synthesis operations automatically. For sufferers of chronic illness, these could provide continuous tailored-dose output of drugs synthesized from the body’s own raw materials or provide ‘scrubbing’ of toxic chemicals, bacteria, or viruses from the bloodstream. Radically new treatment modalities could be devised with such capability. Later, Nanochips may be combined/hybridized with micro-scale MEMS elements for more complex forms of molecular machinery operating in more ambient environmental conditions. These kinds of chips would perform processes like continuous materials extrusion (actually, more like knitting and weaving at a molecular scale), which would be key to the mass production of extremely strong diamondoid materials. Conversely, they could function as low-friction/low-energy cutting or milling devices, stripping materials down one molecular layer after another. These might become the basis of new extreme precision frictionless machine tools or perhaps even frictionless low-energy tunnel boring machines that need very light structures and can synthesize extremely tough and contiguous tunnel linings in-situ by recycling the refined materials they remove. In some of their most advanced multi-functional forms Nanochips may become the basis of fabrication systems based on moveable Nanochip tool heads akin to print-heads in a digital printer or Nanochip array plates. Such devices would be the basis of a generation of ‘fabbers’ as we commonly imagine them today, working roughly like today’s 3D printers but with Nanochip tool heads. This same technology would also work in reverse; as Disassemblers which take apart objects to recycle their basic materials. Some ‘precision disassemblers’ might be employed to record the composition and structure of items in a way that might facilitate their copying. But more generally such machines would employ simple shredders and grinders to reduce material to a more homogenous granular form that could be put in a hydrocarbon solution for disassembly by arrays of fixed-mounted Nanochips. NanoSoup, NanoAspic, and the Materials Internet As various forms of Nanochip Fabbers evolve their users will soon confront a critical problem. Today we often imagine fabbers as relatively modest-sized desktop machines that simply output whatever products we want. What is often overlooked is the raw materials that those products are made from. Early nanofabrication will tend to require materials in relatively bulky forms; many kinds of liquid solutions of refined materials in a process solution of inert hydrocarbons. So, sitting next to that little wonder of a desktop fabber may be huge collections of plastic carboy containers and Parmalat-like paper box liquid containers akin to bulk printer ink all plugged into a complex kludge of thin tubing and plastic manifolds fanning into the back of that machine. As the materials are used-up, the hydrocarbon solution will be left behind as waste material that, to be disposed of easily without polluting the environment, would be converted into a much less bulky form. The regular user of a home fabber of the future may be easy to pick out in his neighborhood as he would be the one putting out trash-cans full of diamond sand with the garbage! Handling these raw materials may become a critical issue for the progress of nanotech-based industry and a possible solution may emerge from a combination of NanoChip and stochastic processing techniques in the creation of NanoSoup. NanoSoup is a generic feedstock solution for nanofabrication that uses molecular packaging to allow many kinds of chemicals, materials, and nano-components to be combined in the same hydrocarbon process solution without reacting with each other. In this way a large combination of materials and nano-components can be kept together in one tank and individually extracted using Nanochip sorters that pick up materials as needed out of the solution, unpack them, and pass them to the processing system. Complimenting this would be a material called NanoAspic; a solid form of NanoSoup where materials are packaged in rigid forms in a solid diamondoid matrix alternately extruded and disassembled by specialized Nanochips. With this technology bulk materials could be shipped or stored long-term in dense solid form, then converted into modest sized working reserve of NanoSoup in a tank in or near the fabber. Once ubiquitous enough in use, this technology could become the basis of a Materials Internet using a pipeline linked to homes and businesses. Using buffers of NanoAspic at strategic storage points (made during off-peak use periods), this pipeline network would provide materials on-demand to users by automatically maintaining constant relative volumes of each type of raw material and components and automatically collect the waste products of processing for recycling. The network would also be connected to materials/components suppliers such as mines and chemical plants, nanocomponent factories, and environmental pollution recovery systems with the automated metering of supply, consumption, and recycling creating an automated materials market. The NanoFoundry and Free Assembler Systems The currently envisioned Holy Grail of nanofabrication technology is the freely mobile nanoassembler robot; a compact nanomachine that is self-mobile in fluid mediums of liquid or gas and performs direct mechanosynthesis on objects in a volumetric environment. Contemporary SciFi typically portrays nanotechnology in this form, in particular in the form of ambient environment nanomachines that can invisibly ‘swim’ through air, self-replicate and build with materials in the ambient environment—which seems so much more magical. That, however, is likely to be one of the most difficult to realize forms of the technology as a result of the abundant hazard of ‘free radical’ ionized molecules in the ambient environment which are, to nanomachines, rather like powerful magnetic sea mines. Whether ambient environment nanoassemblers are even possible may depend on just how much they need to be ‘armored’ against free radicals to survive the environment—they might ultimately be too bulky and encumbered to actually function. But long before such nanorobots are developed much simpler assemblers designed to operate in a sheltered ‘eutactic’ environment are likely to be realized, becoming the most common, universally applicable, form of nanofabrication technology. Evolved from Molecular Carriers, early assemblers will likely be used in inert liquid process solutions and may not be self-mobile, relying largely on stochastic interaction as fluid flows around surfaces being worked on. But unlike the simple carriers, they will be multi-functional, able to manipulate many kinds of molecules and molecular components, and have an internal or external spatial and topological awareness that allows them to sense where they are with some precision and the nature of the surfaces they are near. They may be powered in a variety of ways—this as yet undetermined definitively. They may carry some kind of chemical ‘fuel’, pick it up in process solution, or convert other kinds of energy like heat, light, and ultrasonic vibration. Their basic purpose would be simple; to pick up materials and information from Nanochip supply ports, drift around in gently flowing process solution until they find themselves in the necessary location, unload and install their material payload, then drift away to pick up material again back at the supply ports. In this way, and in swarms of many billions in large volume working areas, nanoassemblers would be able to build extremely complex structures—at the complexity level of living organisms—of very large scale, volumetrically and from the inside-out, possibly employing a nano-extruded scaffolding structure as support and metrology system. Assemblers would be used in tank-like working containers of various size and shape connected to various storage tanks for process fluid and materials and with a variety of Nanochip support systems integrated into them as well as sophisticated cooling systems to deal with the large amounts of waste heat these trillions of tiny machines would generate as they work. In some visualizations, process containers are sometimes depicted as shallow open top tubs in which structures are made top-down using modest volumes of process fluid. But it is likely that early systems would be completely contained. Early assemblers are likely to be somewhat specialized, fragile, and short-lived and dedicated Nanochips or process tanks would recycle and mass-produce them on demand. Controlled by sophisticated computers, we call this collective system a NanoFoundry. Though Nanochip-based fabbers and extruders may long prove to be the mainstay of bulk nanofabrication and casual personal manufacturing, the NanoFoundry would, despite initially being much bulkier and more complex, have great advantages in the complexity, scale, and speed of their production because the entire 3D volume of a product would be simultaneously accessible to assembly rather than just one moving portion of a moving 2D plane. This would be the technology that could produce prosthetics and robots indistinguishable from living organisms, computers as complex as the human brain, and objects on the scale of whole vehicles and buildings. And, of course, the assembly process could work in reverse with the advantage of this type of system being the elimination of the contrivance of mechanical shredders and grinders to reduce material to a more manageable state. Over time assembler design would evolve increasing multi-functionality, on-board intelligence, intercommunication for cooperative activity, durability, and the option of self-mobility to allow for ever-faster more carefully controlled activity. This would enable a host of medical applications where more medical-specialized assemblers would be deployed within the human body to perform a vast assortment of tasks. They could perform ‘surgery’ down to a molecular scale, repairing cells from their insides and actively seeking-out damage, abnormality, and infection. They might stop and reverse aging at the cellular level. They could fabricate enhancements of various kinds such as artificial high-performance blood cells, cosmetic changes to skin, tissue, and bone structure. They could fabricate grown-in-place body-powered interfaces for wireless digital communication and parallel sensory communication. However, these medical assemblers are likely to be short-lived because the human body is a much more harsh environment than the purified hydrocarbon process solutions of a NanoFoundry. Thus the medical Nanochip implants of previous generation technology would give way to implanted or made-in-place artificial ‘organelles’; microscopic organ-like implants whose job would be to sense conditions of the body and manufacture and deploy medical nanoassemblers on-demand from the supply of materials within the body itself. NanoFoundry technology would also find alternative applications in mining and excavation. Using injection tubes and water-tight bulkheads or caps, disassembler nanobots could extract materials from the ground without excavation using networks of microtubes. This would also be a powerful means of restoring toxic waste sites and abating many kinds of environmental pollution. Once impossibly difficult and costly tunneling operations would be performed by installing trail marker probes along a desired tunnel path then installing bulkheads with Nanochip extraction and supply ports, filling the space behind them with process fluid, and letting disassemblers tunnel their way along molecule by molecule, delivering the removed material as refined material output or recycled by assemblers into extremely durable wall shells made as the tunnel advances. With such an economical fully automated means of excavation at hand a global materials internet, comprehensive use of geothermal energy, and things like global super-speed subways would all be almost negligible in cost to realize. Assemblers would also find application in self-repairing and self-upgrading systems, though initially limited to machines that could host their own liquid process solution much like the human body hosts blood in a vascular system. Likely uses would be in advanced high-reliability computers and life-like robots that would host their own Nanochip assembler recyclers and where such fluids would, as with a NanoFoundry, have the dual function of both hosting assemblers and serving as a cooling fluid. Eventually, such technology may evolve to produce polymorphic composites; structural materials that not only have a self-repair capability but also the ability to radically alter their shape or other physical properties for different modes of use or activity. NASA has already speculated on the possibilities of such materials and in TMP2 we discuss the eventual development of spacecraft that re-configure themselves to suit different modes of transit, such as simple symmetrically-shaped rockets that reform themselves on-orbit to become re-entry lifting-body or winged vehicles later. Assemblers may also be able to function as molecular builders, serving roles akin to catalysts and filters in otherwise homogenous solutions. Specialized nanobots may be designed for such purposes as well, assuming jobs previously done with Nanochips and, though likely to be very short-lived, could even perform such functions in the ambient environment. These could find uses in abatement after oil and chemical accidents. (though the net impact of nanotechnology by this time might very well obsolesce fossil fuel use completely) Chrysalis Systems and Portable NanoFoundries As NanoFoundry technology develops it would encounter a certain stumbling-block in the limitations imposed by the need to contain assemblers and process solutions in tanks. People are always inclined to seek portability and flexibility with their tools and while most of the other active systems of a NanoFoundry are likely to shrink to remarkably tiny size, they may still be critically limited by the pre-established size of bulky process containers and large heavy volumes of process solution. Thus we anticipate a compulsion to find some kind of on-demand recyclable structure that can be fabricated in the ambient environment to serve as an on-demand specialized process container unlimited in shape and size and able to minimize necessary process fluid volume by their topology. We call such a structure a ‘chrysalis’, after the pods that insects, such a butterflies and moths, often employ in the metamorphic phases of their life-cycles. Chrysalis systems would allow NanoFoundries to become quite small and portable while supporting fabrication of items of extremely large scale, as long as a necessary supply of materials—likely from the Materials Internet—is at-hand. The development of chrysalis systems may likely result from the combination of made-on-demand scaffolding structures used in conventional NanoFoundries and skin structures based on layers of flexible platelets akin to those of human and plant epidermis. Scaffolding structures would be microscopic space-filling space-frame systems that allow the free flow of process fluid and assemblers while providing attachment points for structures under assembly, allowing process structures that cannot support themselves under gravity to be volumetrically supported as they are built. As these objects are made the scaffolding around them is selectively removed to make room. Scaffolds also would provide a molecularly precise metrology grid assisting assemblers in their navigation and would provide supports to mount temporary support and communications systems assisting assemblers near their working sites. In earlier forms of NanoFoundries scaffolding structures would be rather generic and possibly produced by Nanochip extruders in fixed positions inside process tanks. But with chrysalis systems they would be made in very custom forms tailored to the topology of the objects they are internally supporting and covered in a tough but flexible skin. This skin would not be permanently attached to the scaffold and at periodic stages of processing hydrostatic pressure inside the chrysalis would be increased so the skin would be detached from the scaffold and slightly, selectively, inflated, creating a gap that assemblers would fill with addition scaffolding and skin platelet elements. In this way the process fluid volume would be kept within a relatively small volume between the chrysalis skin and the outermost surfaces of the object under fabrication and the chrysalis could progressively grow and change in shape as production progresses. Because the chrysalis would be assembled by free-roaming assemblers using parts mass-produced by specialized Nanochip generators, it would have unlimited potential size and shape and, instead of being extruded, would grow from a tiny port on a portable NanoFoundry enclosure creating a kind of umbilical connection to the NanoFoundry’s systems. Once fabrication is complete, chrysalis structures would recede from around the objects made and be recycled. Their scaffold and skin would be designed to collapse in controlled ways as hydrostatic pressure is removed and the pieces of the structure carried away by fluid flow and active disassembly to be recycled. Chrysalis systems might also grow a number of support systems in their own surfaces, such as leaf-like accumulators that draw carbon from the air, provide heat sinks, and gather solar energy or root-like elements that burrow into the ground to draw materials from soil, earth, and rock. There would also be medical applications of chrysalises. Made of diamondoid materials, these structures would be quite resilient and provide good protection. Thus it would be possible that for people who need to fabricate a replacement limb, the chrysalis inside which it is being fabricated could serve double-duty as a crude prosthetic. Chrysalises could also function like bandages and casts covering wounds as they are being repaired. Rather like the chrysalises of butterflies from which their names derive, they could also largely cover and protect a whole human body that is being extensively repaired or augmented. Chrysalis structures would be, in materials terms, relatively costly and time-consuming things for a NanoFoundry to produce and so, while potentially being a mainstay of portable NanoFoundry use, would not be efficient for things requiring rapid mass production. For that dedicated container systems would still have a distinct advantage. But the ability of chrysalis structures to host truly huge objects—things the size of large vehicles and buildings—would open new possibilities for holistic nanofabrication. NanoFoam As the development of portable NanoFoundries and chrysalis systems progresses, it is likely that engineers and users will come to realize the increasing redundancy of some of the hardware they use. Generally, users would operate NanoFoundries by external user interface devices like hand-held PADs and other devices and the systems contained within a typical NanoFoundry—computers, communications systems, Nanochip ‘generators’ for assemblers, microcomponents, and chrysalis components, materials supply interface ports—would all be reproducible as equivalent ‘organelle’ units—much like medical artificial organelles—mounted in the scaffolding and skin of a chrysalis itself. Thus the idea of a NanoFoundry would itself become redundant. All that a NanoFoundry does could be contained within a persistent starter chrysalis reduced to some easily carried pod-like shape that one plugs into the nearest Materials Internet port and grows into the necessary shape to fabricate whatever it is told to make, returning to its pod-like form afterward. And, of course, these pods would be able to self-replicate by simply dividing like some giant version of an animal cell. Such pods could be pre-programmed to produce items and planted in the ground like seeds or thrown into the sea, extracting energy and materials through their skin from the ambient environment around them. As we noted, because their internal scaffold structures and skin are made of diamondoid materials, chrysalis structures would be quite resilient and able to integrate a variety of functional elements and physical features. Once one has realized the redundancy of a separate NanoFoundry system it is thus only a small leap of logic to the realization that a chrysalis itself can assume the forms and functions of useful things. It can ‘become’ things instead of ‘making’ them, activating its internal assembler systems to self-transform as necessary to suit a user’s needs, recycling its own material. This would not necessarily be a very rapid process. As we noted, chrysalis systems would have a trade-off in performance compared to the dedicated NanoFoundry. But this would be a tiny price to pay for such incredible flexibility. Thus we arrive at perhaps one of the most significant milestones in nanotechnology development of the future; NanoFoam. NanoFoam is an evolved form of chrysalis technology designed to self-transform in order to become things rather fabricating them, forming functional internal elements, reinforced structure, and systems as needed and tailoring its external skin to simulate the feel, appearance, and properties of most any other kind of material, hard to soft, smooth to rough. Within its physical make-up it would contain all the elements of a NanoFoundry as redundant microscopic organelles activated as necessary to change its form and internal features or perform self-repair. Likewise, within this structural matrix would be extensive redundant computing and communications systems allowing all artifacts made with it to be ‘smart’ objects sensing the external environment, communicating with each other and users by various means, and functioning as an extension of the global Internet. It’s large stationary forms, such as buildings, would integrate directly into the Materials Internet, becoming integral to a global communications and materials infrastructure. It could replace the need for discrete computers and communications devices and even become host to a collective distributed intelligence which would aid its communication with users and its sustainable presence in the natural environment. This is the basis of the concepts of RhiZomes and BioZomes as described elsewhere in TMP2. Able to reproduce the characteristics of living matter, NanoFoam would readily integrate with the human body through organelles and prosthetics, allowing every human being the option to carry, in their own bodies, the entire industrial potential of the civilization. As technologies of artificial intelligence, cognitive augmentation, and consciousness transition develop, NanoFoam could become the common alternative to an organic human body, completely freed from the aesthetic and functional limitations of biology. Should NanoFoam be realized it would embody virtually all the capabilities long anticipated for nanotechnology at a much lower level of technology than may ultimately be necessary to produce things like Ambient Environment Assemblers. In TMP2 we anticipate NanoFoam becoming the basic physical matrix of future civilization, its core infrastructure, and the basis of most of the built habitat. The basis of our cities, the means to constructing with ease the many kinds of space habitats and spacecraft of the Solarian era, and the chief tool of interstellar settlement. Ambient Environment Assemblers The commonly envisioned ultimate form of nanotechnology is the Ambient Environment Assembler; a universal nanobot that can communicate, self-replicate using materials around them, and operate freely in the ambient environment, invisibly permeating all porous materials, our own bodies, and freely mobile in air and water. Using some form of wireless communications, remote computers would direct Ambient Assemblers to coalesce at any location to perform nanofabrication using materials in the environment around them—carbon from the atmosphere being the predominate raw material. Ambient Assemblers would essentially turn the ambient natural environment into a kind of total area NanoFoam, seemingly producing artifacts on demand from thin air. Such assembler technology is probably the most challenging and advanced form of nanotechnology possible—orders of magnitude more advanced than even NanoFoam would likely be. The ambient environment, with its abundance of free radicals, temperature extremes, static electricity, violent fluid dynamics, large communications distances, and so on presents daunting challenges to nanomachines. The physical armor that such ambient environment nanomachines may need to survive for any length of time may encumber them beyond any home of independent mobility. But there is also an important question of whether such advanced forms of nanotechnology would even be needed generally given the great capabilities of NanoFoam technology that may likely precede it. There would be relatively few capability advantages to it, though it could radically change the nature of our relationship to the natural environment and could change the basic strategy of interstellar settlement by allowing civilization to fill space with drifting nano-spores to spread its core infrastructure across the stars. Diamond Age Living As we can see in this discussion, the wonders anticipated for nanotechnology may not be far-off the mark, but they will most certainly not be realized all at once and we can see a specific development path with specific bottlenecks. But even before realizing the full capabilities we envision, the technology will have great impact on our built habitat and lifestyles. Even early on we can see big changes likely in the physical composition of our civilization, its energy overhead and environmental impact. We can foresee the realization of new architecture with radically light expansive characteristics. We can see how many now costly materials in our infrastructure may be replaced with diamondoids and, in some cases, remarkable diamondoid metamaterials; materials whose chemical, electrical, thermal, and optical properties are determined by artificial nano-scale structures rather than direct natural physical properties. Diamondoid-based aircraft and spacecraft may realize seemingly ridiculous payload mass fractions as their structural mass radically shrinks. But perhaps the most dramatic impact of all may be the way nanofabrication changes how our civilization works at a fundamental economic level by its increasing ability to produce complex products with systems of increasingly small scale and increasingly comprehensive automation—a long-term trend in our industrial history clearly played-out across the 20th century. With the realization of a Materials Internet, there may be almost no goods transportation left in the global economy; only these raw materials whose production and distribution are automatic, demand-driven, and comprehended by artificially intelligent systems at a level far deeper than humans can manage. And it is from that eventuality that the idea of a post-scarcity culture emerges. Products become information made physical on demand. Energy is utterly decentralized, ubiquitous. Resource production and recycling is totally automated, invisible, near-zero-impact, and exchange becomes commodity-based, demand-indexed, digitally mediated, and independent of any currency. Finance as we understand it becomes redundant, irrelevant, along with many Industrial Age political constructs. Capital becomes a meaningless term, replaced by social capital/credit. Even if we never realize the full tableau of wonders imagined by Singularity futurists, the world promises to be a very different place indeed in the Diamond Age.